a. Relates to wage and salary workers from 1937 to 1950. Beginning in 1951, includes self-employment. Reported taxable earnings include Social Security taxable wages as reported by employers and Social Security taxable self-employment income as reported by self-employed individuals. See Table 2.A3 for annual maximum taxable earnings.

b. Excludes railroad account numbers. Since program began, 453.7 million Social Security numbers have been issued. Some individuals have been issued more than one number.

c. Workers reported with first taxable earnings under program in specified year. From 1937 to 2008, 342.1 million different persons reported with taxable earnings.

d. Total wages, including estimated amounts above taxable limit, from 1937 to 1950. Beginning in 1951, also includes reported total net earnings of self-employed persons.

e. Preliminary data.

f. Taxable earnings are preliminary estimates based on Social Security data; employment data are preliminary estimates based on data from Bureau of Labor Statistics.

g. Preliminary estimates based on data from Bureau of Labor Statistics and the Bureau of Economic Analysis.

a. Represents total number in specified type of employment. Persons with both types of covered employment during the year are included in each type.

b. Total wages, including estimated amounts above the taxable limit.

c. Reported self-employment net earnings.

d. Includes Social Security taxable wages as reported by employers and Social Security taxable self-employment income as reported by self-employed individuals. See Table 2.A3 for annual maximum taxable earnings.

e. Preliminary data.

f. Taxable earnings are preliminary estimates based on Social Security data; employment data are preliminary estimates based on data from Bureau of Labor Statistics.

g. Preliminary estimates based on data from Bureau of Labor Statistics and the Bureau of Economic Analysis.

a. Most state assignments are based on end-of-year residence obtained from electronically filed employer wage reports; the remainder are based on location of employer from reports filed on paper.

b. Workers with earnings in both wage and salary employment and self-employment are counted in each type of employment but only once in the total. National and state totals and subtotals are unduplicated counts of workers in each type of employment.

c. Includes Social Security taxable wages as reported by employers and Social Security taxable self-employment income as reported by self-employed individuals. Annual maximum taxable earnings for Social Security (OASDI) from a single employer or from self-employment were $102,000 in 2008. Totals do not necessarily equal the sum of rounded components.

d. For 2008 earnings, paid at the rate of 6.2 percent of taxable wages by both employees and employers, 6.2 percent of taxable tips by employees, and 12.4 percent of self-employment income by self-employed workers. Data are unadjusted for multi-employer tax refunds. Totals do not necessarily equal the sum of rounded components.

e. Persons employed in American Samoa, Guam, Northern Mariana Islands, and U.S. Virgin Islands; U.S. citizens employed abroad by U.S. employers; persons employed on U.S. oceanborne vessels; and workers with unknown residence.

a. Workers with earnings in both wage and salary employment and self-employment are counted in each type of employment but only once in the total.

b. Includes Social Security taxable wages as reported by employers and Social Security taxable self-employment income as reported by self-employed individuals. See Table 2.A3 for annual maximum taxable earnings.

d. Data are unadjusted for multi-employer tax refunds. Unadjusted for tax credits. See Table 2.A5 for information on tax credits.

e. Preliminary data.

f. Taxable earnings are preliminary estimates based on Social Security data; employment data are preliminary estimates based on data from Bureau of Labor Statistics and the National Income and Product Accounts.

g. Preliminary estimates based on data from Bureau of Labor Statistics and Bureau of Economic Analysis.

a. Most state assignments are based on end-of-year residence obtained from electronically filed employer wage reports; the remainder are based on location of employer from reports filed on paper.

b. Workers with earnings in both wage and salary employment and self-employment are counted in each type of employment but only once in the total. National and state totals and subtotals are unduplicated counts of workers in each type of employment.

c. No annual maximum taxable earnings amount for Medicare. Totals do not necessarily equal the sum of rounded components.

d. For 2008 earnings, paid at the rate of 1.45 percent of taxable wages by both employees and employers, 1.45 percent of taxable tips by employees, and 2.9 percent of self-employment income by self-employed workers. Totals do not necessarily equal the sum of rounded components.

e. Persons employed in American Samoa, Guam, Northern Mariana Islands, and U.S. Virgin Islands; U.S. citizens employed abroad by U.S. employers; persons employed on U.S. oceanborne vessels; and workers with unknown residence.